The heart functions under normal conditions through electrical impulses that originate in a group of cells located in the right atrium, producing a regular rhythm and at a frequency adapted to the needs of each individual.
Atrial fibrillation is the most frequent arrhythmia (heart rhythm abnormality) in the population, in which, the electrical activity of the atria becomes a real chaos, appearing simultaneously in many areas of the atria and at great speed. This has two consequences:
- The atria stop contracting and blood flow backs up within them.
- The rest of the heart contracts irregularly and at an excessively fast rate for the patient’s activity.
Atrial fibrillation may occur in the form of time-limited crises (minutes or hours) and disappear spontaneously, or it may continue indefinitely and require medical help to interrupt the arrhythmia.
What causes atrial fibrillation?
There are several factors that favor the appearance of this arrhythmia. The most important of these is age, against which there is little we can do.
However, there are many other causes of atrial fibrillation that can be modified or treated, such as obesity, sedentary lifestyle, poorly controlled hypertension, sleep apnea, excessive alcohol consumption or smoking.
Curiously, some patients present this arrhythmia without any specific cause, appearing in young people with healthy lifestyles, and even in athletes.
Does it have symptoms?
Atrial fibrillation produces two types of symptoms. On the one hand, those derived from the rapid and irregular contraction of the heart such as palpitations, chest pain, shortness of breath, dizziness, etc. On the other hand, in certain patients it can cause much more serious symptoms as a result of the detachment of a clot from the left atrium that impacts the brain, known as a stroke, which can manifest itself as a sudden loss of mobility, speech or vision.
What is the difference between a healthy heart and one with atrial fibrillation?
Atrial fibrillation occurs in both “healthy hearts” and those with other types of problems (e.g., valve lesions, coronary artery blockages or heart muscle disease).
It should be noted that atrial fibrillation produces over time a progressive dilatation of the atria that favors the arrhythmia to become chronic. This is why we say that “atrial fibrillation causes atrial fibrillation”; consequently, it is important to treat the arrhythmia in early stages to avoid this remodeling in the atria that reduces the chances of recovering normal rhythm.
How is this disease diagnosed?
Diagnosis is relatively simple as it is made by means of an electrocardiogram, which is obtained very simply by placing a series of patches (electrodes) on the chest.
However, in patients with brief symptoms it can be more complex to identify whether or not they are episodes of atrial fibrillation. For this purpose, we have electrocardiograms that record the rhythm over 24 hours (Holter recordings) and, more recently, innovative tools such as smart watches or mobile devices capable of making an electrocardiographic recording at any time for subsequent interpretation by a cardiologist in the consultation room.
How can the consequences of atrial fibrillation be avoided?
Stroke, the most dangerous complication of atrial fibrillation, can be prevented by taking anticoagulants. Anticoagulants are drugs that decrease blood viscosity and prevent thrombus formation in the heart, so they are indicated in most patients with atrial fibrillation.
Can we cure atrial fibrillation?
Initial treatment of atrial fibrillation is usually with antiarrhythmic drugs, which are often poorly tolerated and have limited efficacy. Fortunately, we can now say that, in a large majority of patients, atrial fibrillation can be definitively eliminated through an intervention called pulmonary vein ablation.
Pulmonary vein ablation is a minimally invasive procedure consisting of the elimination of the electrical activity originating in the veins that connect the lungs to the heart, through the application of radiofrequency (heat) or cold at the mouth of the pulmonary veins.
Performed by expert electrophysiologists, electrical isolation of the pulmonary veins is a very safe procedure that definitively maintains normal rhythm in approximately 70% of cases and improves the patient’s symptoms in more than 90%.